When a medicinal solution is administered to an admitted patient in a medical facility such as a hospital, the medicinal solution is often prepared by mixing different types of medicinal solutions obtained from different medicinal solution containers. Such a conventional mixing operation to prepare the medicinal solution often requires manpower of medical personnel such as nurses or pharmacists. An injection needle, for example, is manually inserted in the different medicinal solution containers to suction the medicinal solutions therefrom. This is a heavily time-consuming work for the medical personnel. Particularly when the medicinal solution is suctioned from a sealed medicinal solution container, for example, a sealed vial container, it is necessary to introduce air into the medicinal solution container during the suctioning of the medicinal solution therefrom (generally called pumping work) in order to adjust an internal pressure of the container. Thus, it imposes even a more time-consuming and complex work load on the medical personnel to suction the medicinal solution from the sealed container. Some of the medicinal solutions used in medical facilities need to be cautiously handled with a great care for safety. Under the circumstances described so far, there is a strong demand for a medicinal solution injection apparatus and a medicinal solution injection method that enable safe handling of any medicinal solutions with less work load.
FIG. 16 is a structural view of the medicinal solution injection apparatus disclosed in the Patent Literature 1. The medicinal solution injection apparatus illustrated in FIG. 16 is configured to inject a solution 4 from any of a plurality of liquid bottles 3 into a medicinal agent bottle 1 to dissolve a powdery or particulate medicinal agent 2 in the medicinal agent bottle 1. As illustrated in FIG. 16, a compressed gas feeder 5 feeds a compressed gas into a space above the solution 4 in the liquid bottle 3 through an injection needle 7 by using a feed pipe 6 to thereby press the solution 4 at an adequately higher pressure than atmospheric pressure, so that the solution 4 is injected into the medicinal agent bottle 1 through a feed pipe 8. There are provided opening/closing cocks 9 between the injection needles 7 of the liquid bottles 3 and the feed pipes 6, and also between the injection needle 7 of the medicinal agent bottle 1 and the feed pipe 8. The opening/closing cocks 9 are usually kept closed, but any of the opening/closing cocks 9 that needs to be used is opened among the opening/closing cock 9 of the liquid bottle 3. In the illustration of FIG. 16, the opening/closing cock 9 of the liquid bottle 3 on the right side and the opening/closing cock 9 of the medicinal agent bottle 1 alone are opened, and the solution 4 is currently injected into the medicinal agent bottle 1. The apparatus according to the Patent Literature 1 is designed to safely inject the solution 4 into the medicinal agent bottle 1 semi-automatically by using the compressed gas while using no manpower.